Friction shock-absorbing mechanism



Feb. 28, 1928.

J. F. OCONNOR FRIGTION SHOCK ABsoRBING MECHANISM Filed May 2, 1925 Z Sheets-Sheet, l

Patented Feb. 28, "1928.

unirse vevitarse earner JOHN F. oconivoit,` or CHICAGO, ILLINOIS, Assienon To w. n.' Minna, INC., or

insane CHICAGQILLINOIS, .a CORPORATION or DELAWARE.

FRICTION SHOCK-ABSORBING MECHANSM.

. Application filed May 2, 19.25. Serial 110.22380.

This invention relates to friction shock absorbing mechanisms.

One object of the invention is to provide a shock absorbing mechanism having graduated preliminary action, heavier linal resistance.

Another object of the invention is to pro-A vide a shock absorbing mechanism of high capacit-y, especially yadapted for railway draft riggings, wherein a graduated action is obtained, the resistance offered during the compression-stroke increasing progressively.

A-still further object'of the invention is to provide a mechanism of the. character indicated, having graduated initial frictional resistance, followed by final relatively heavy frictional resistance produced by relative movement of a plurality of friction plates.

Still another object of the inventionV is to provide a frictionV shock absorbing mechanism having graduated preliminary combined spring vand frictional resistance and heavier final resistance, v wherein la V,relatively heavy wedging action is had and release of the mechanism is assured by a lateral wedging pressure creating means comprisingelcments having coacting keen wedging faces and coacting blunt wedge faces. .v

A more specific object of the invention is to provide a shock absorbing mechanism including a friction casing; a plurality of relatively movable intercalated friction plates,

certain of which are anchored to the casing, together with combined lateral pressure creating means frictlonally cooperating with certainof the plates and the friction shell;`

and relatively light and heavy spring resistance elements, wherein graduated ylight preliminary action is had, during which l-relative movement of the pressure creating means and plates is resisted successively by y the light and heavy spring resistance elements, the preliminary action being followed by a heavy frictional resistance during which the friction plates move relatively to each other. Y Other objects and advantages ofthe invention will morer clearly and fully appear from the description and claims hereinafter following. p

In the ldrawings forming apart of this specicat-ion,Figure 1 is a longitudinal, hori- Zontal, sectional view of a portion of a railway draft rigging, showing my improvefollowed by ments in' connectiontherewith.` Figure 2 is a front-end, elevational view of the shock absorbing mechanism proper. Figure 3 is a wedge friction shoe and one of the frictionA l plates employed in connection with my iin- 1.

proved mechanism. y l

ln said drawings, lO-.lO indicate. channel-shaped center or draft sills of Ia railway car underframe, to the inner faces of which are secured front stop lugs ll-ll and rear stop lugs l2-.12 The innerendportion of the drawbar is indicated'atl, to which is operatively connected a hooded yoke 14 of well known form.l mechanism proper, hereinafter more fully described, as well.` as a main follower 15ers .disposed within the yoke. The yoke and the parts therewithin are supported .in operative position by a detachable saddle plate My improved friction shock absorbing mechanism,v comprises, broadly, a combined springl cage and friction shell casting A; twin arranged main spring resistanceelements B-*Bg a set of relatively fixed fric- The shock absorbing tion plates C-C; a setof relatively movable friction plates D-Dg an anchoring -element or plate E; two wedge blocks F-Fg two keen angled vfriction shoes Cir-G; two i blunt angled friction shoes Hv-H; four auX- iliary spring resistance elements 4J-'J 5 ttwo pressure transmitting blocks K- Kg a main spring follower. L'; two movable combined wear plates M--M, whichfunction as plate restoring elements; and two retainer bolts .N-N. Thecombined spring cage and friction shell casting is of generally rectangular outline, `having spaced horizontally disposed top and bottom walls l-f-l, vertically disposed side walls l7-l7,a nd a transverse vertical end wall 18v adapted to cooperate with the stop lugs Vl2 in the manner of the usual rear follower. VThe side walls of the casting A are left open, as most yclearly `shove ie 'Figures '1, 3. and site Permit Shtt- 1 ing of the outer coils in assembly, the follower and twin arranged inain spring resistance element B being inserted frein front end of the friction shell scction.- The forward end of the casting A Yprovides a friction shell', the side walls having opposed,

interiorffriction surfaces 19H19 converging inwardly of the nieehanisni.v

l The friction plates C and D are arranged in a centrally disposed group at the forward end of the casting A, theplates D which are niovable being alternated with the 'plates C which are fixed tothe casting A as 'hereinafter niore Vfully described. Thev group of friction plates coinprises preferably four movable plates and live fixed plates'7 two of the i'ixed plates being arranged outerinost and cooperating with twin arranged lateral pressure creating means .hereinatter incre fully described. The friction plates C and D are all of identical construction,except asphcreinafter pointed out. Each plate C and D, as inost clearly shown iii `li`igure 7,

`-is .preferably forinedof hard steel and is substantially rectangular in' lshape. As inost clearly shown in Figure 7, the plate C is ofV substantially T-shape in horizontal section,A beingl provided with lateral flanges 20e-20' at the vrear endthe'reof. The section l*forming the flangesQO project-s above the f, top and Vbottoni edges ofthe pl ates,'thereby providing lugs Q1 fora purpose hereinafter described. All of the plates C and D with the exception of the two outermost plates C i and D at each side of the group have the flanges 2O extending on both sides thereof,

vthe latter plates having the `flanges eut awayl at the outer side as shown most clearly in Figure 1, thereby presenting continuons friction surfaces for the entire length of the plates. i

The plates C areanchored to the castingA bv an anchoring` cleiiient E. 'The' anchoring clc'ii'ientlil comprises a transversely disposed. vertical, heavy pla alike section 2Q having horizontally disposed right angled projections 23-23 at the top and bottoin thereof.. the Vlatter being` provided wth transversely y Vextending vertically disposed ribs Qal, thereb7V Jresentino transverse slots 25-25 Vat the stop' and bottom of the retaining n'ieinber adapted to aceoininodate'the corresponding lugs @1f-2l of the plates C. lt will be evi-' dent that when the lugs 21 or the plates C are engaged within the slots 2, they will be held in fixed relation to the casting A, being restrained from out Yard movement by the ribs The top and bottoni walls 16416 ot the 'casting A are profi-'ided with .vertically alined transversely disposed, Velongated openings 26-26 adapted to accoininodate the top and bottoni sections YQitrof the anchoring clement.

rlhe wedge blocks F are arrangedin pairs at'opposlte sides Aof the mechanism. Each wedge block F, as shown, is in the forni of a casting which is suitably vcored and has a flat front face 27 adapted to kbear on the inner face of the inain follower 15. At the inner end, each block ispi-ovided with twoVr .of the wedge blocks F. Each shoe H has a longitudinallydisposed vtriction surface 119 adapted to cooperate with the corresponding friction surface 19 of lfthe friction shell.

On the inner side, each shoe H is provided with a. lateral enlargement 30 having wedge face'129 at the forward end thereof, i

correspondingly inclined to and vadapted to `cooperate with the face' 29 of the corresponding wedge block F.` Rearwardly of the wedge face 129 the enlargement of the shoe H is cut away to accommodate the rear pertion of the rcooperating wedge shoe G. At its rear end, each wedge slice H hasa lateral extension 31 adapted toforin` an abutment for the rear end of the co-operating shoe G and also an abutinentsurface for the front end of thecooperating,auxiliary spring resistance elements `J-J.' i

The two wedge shoes G are lalso of like construction, each shoe having a wedge face 128 the outer end thereof, correspondingly inclined to and adapted to cooperate with the wedge face 28 of the Corresponding wedge block M. s most 'clearly Vshown inl Figures 1 and 6, the rearend of'eachfwedge friction shoe G is eut away to accommodate the lateral projection 31of the correspondingshoe H.. Each of the shoes Gr is also provided with a longitudinally'disposed friction surface at the inner side thereof adapted to cooperate with the corresponding outermost fixed friction plate Col the group. Y

lhe spring follower L is in the form of a relatively heavy, substantiallyv rectangular plate having'its front facenorinally 'bearing Von therear face of the vertical of the anchoring element E.

, The main spring resistance elements B--B preferably comprise twin arranged ineinbers.

each member consisting of a relatively heavy vouter coil and a relatively lighter inner coil,

the inner coil of each ineinber being held in .centered position by lugs 33 and 3l, proiect ing respectively frein therear wall 18 of the casting A and the "rear side of the sorinfr follower plate L. Y l w The auxiliary spring resistance elements J are k'preferably four in number, being'arranged .in pairs at oppositeV sides vof the mechanism. Each pair ofcoilstliis intersection 22 f vposed between the main spring follower and the inner end of the corresponding friction wedge shoe H. l

The pressure transmitting blocks Kare of similar design, o-ne of the same being disposed at each side of the centrally arranged group of friction plates. rI he blocks K are the same being slightly spaced from the inner end of the corresponding friction shoe H, as most clearly illustrated in Figure 1. Each block is provided with a. pair of recesses -.35 adapted'to accommodate the corresponding auxiliary spring elements J.

The two wear plates M are disposed respectively abo-ve and below the friction plates and wedge pressure creating systems and are adapted toslide on the inner surfaces of the top and botto-m walls of the casting A. Each of the plates Mis centrally cut awayrat the forward end, as indicated at 36, to accommodate the top and bottom lugs 2l of the movable friction plates D. At the rear end7 the central portion of each plate M is also cut away, as yindicated at 37,' toprovide clearance for the anchoring element when the-mechanism is fully compressed. As most clearly illustrated in Figures 1 and 4, the wear plates M normally bear at their rear ends on the spring fol! lower L and at their forward ends engage the lugs 21 of the movable plates D.

The mechanism vis held under initial compression and maintained of uniform overall length by the tworetainer bolts N, one of the bolts being disposed at each side ofthe mechanism. Each of the bolts N is anchored respectively to the casting A and the wedge block F at the corresponding vside ofthe mechanism, the head of the bolt being accommodated in an opening in the vcorre,- sponding boss 33 on the rear wall 18of the casting A and the head of the bolt working in the cored opening ofthe corresponding wedge block F. The wedge friction shoe-s G and H, the pressure transmitting blocks K and thespring follower L are recessed to freely accommodate the shanks ofthe bolts, suflicient clearance being` provided for the necessary lateral lmovement of thewedge friction shoes H.l l

The parts are so proportioned and arranged that the outer ends of the movable friction plates D are normally spaceda predetermined dist-ance from the innerface of the followerv 15 to provide for preliminary action of the mechanism, before any relative movement of the friction plates is had. In this connection it is pointed out that'the space left between the outer ends of the plates D and the'main. follower`15 is appreciably greater than the clearance between the inner ends of the friction wedge shoes H and theI pressureftransmitting blocks K. ln Vassembling the mechanism, the twin arranged main springs vB Vare first assembled with the spring cage, Vone ofthe large coils thereof being `firstl entered into the spring cage through Athe front end of the friction shell. This coil is then vlaterally shifted to permit insertion of the other large coil in a similar manner, the opening in the corresponding side-.wall ofthe shell permitting the necessary lateral shifting of the first named coil.y After theftwo large coils have vbeen placed in position, the two. small coils are telescoped therewithin. The mainspring follower is then inserted through the front end ofthe friction` shell. The anchoring elementE is then kplaced in position. The anchoring element forms an abutment for vthe spring followerV limiting its outward movement therebyl maintaining the twin springs B under .initial compression. The stationary friction plates arev next assembled with the mechanism by passing theminto thecasting from the forward end on either side yof the anchoring element and bringing the lugs 21 thereof VJin alinement witlithc recesses 25. The plates are then slid* laterally to dispose the lugsrQl in the top and bot-tom recesses 25 of the .anchoring element E with the rear endof each plate abutting the vertical section Q2of the anchoring element ,and the front face of the lugs 21' engaging the ribs 24 thereof. The pressure transmitting blocks K,r auxiliary spring resistance elements'J, the wedge systems com-v prising wedgefriction shoes G and H, thev are then placed in position `and the movable plates -D intercalated with' theL stationary wedgeblocks l?, and the ftwo wear plates M friction plates C. The bolts N'are then anchored to the'casting A and the wedge blocks F and thc'nuts of the .bolts are so',

under initialcompression.

The operation of my improved shock' al adjusted as toplacc the auxiliary springs J v'sorbinginechauism, assuming a compression stroke, is asfollows: The follower 15 and the casting A are moved relatively toward each other, forcing the wedge blocks rFinl wardlv of themechanism, pressing the friction vshoes into tight frictional engagement with the friction surfacesof the shell Aof the casting A and the central group of interi cala ted Lfrictionv plates andk also carrying the shoes rearwardly of the casting A relatively vto the fixed plates ofsaid group. The preliminary springs J will thus be. compressed no wedging' action between the'blunt faces i .of thewedges and the corres'pondingshoes yfifi H, `while a true wedging action will be effected between the cooperating keen faces of the wedges F and the shoes G.V Due to` the wedgiiig action, there will be a slight eX- pansion of the shell, thereby storing up energy therein, whereby the vshell will forcibly contract when the actuating pressure is removed, creating lateral inward pressure on the blunt faced shoesH and H and facilitating release of the main-wedges due tothe releasing angle of the cooperating wedge faces of the main wedges and the shoes H. As the operation of the mechanismV continues, compression of the auxiliary springs J will be limited bythe rear ends ofthe friction slices H coming into vengagement with 4the pressure transmittingblocks K, whereupon the follower L will be carried rearwardly in unison with the friction wedgesystems compressing the main spring esistance elements B. During the described action, f friction shoes H and G of each wedge sys- Vtem and the frictionysurfaccs of the shell 25 andfouterinost fixed plates. Due to the con`v Vverging relation of the friction surfaces of the shell, ythe blunt angled shoes will be coinpelled to move laterally inwardly, slipping -on the faces 1290 the wedges lF and effectingan inward movement ofthe shoes H vwith reference tothe shoes Grandan additional compression of the auiiiliary and main spring resistance elements.A F rom the preceding description, talzen in connection with theY drawings, it willbe evident Athat two stagesof preliminary action -aie provided for, the auxiliary'4 springs J Vbeing coniypressedl duringy the first stage and the main springl resistance elements B being compressed during the second stage. During the further compression of the mechanism, the inwardly-moving follower l5 will engage the outer ends of the friction plates D and carry thesame inwardly with reference to the .fixed fiction plates C, thereby greatly augmenting the friction resistanceV offered during the lremainder of the compression stroke. rThis action will continue until the actuating force is reduced or until the follower 15 engages the outer end of the casting A, whereupon the compression of the springs B will Vbe limited and the force transmitted directlythrough the casting A to the Vstop lugs ofthe draft sills. Inthis coniiectiorn,attention is called to the fact that as the mechanism is compressed during the second stage of the preliminary action,

therspring follower L will be moved out of engagement with the inner ends ofthe top yand bottom wear plates M and that this spaced relation will be maintained during the remainder of the compression strol-:e

'while the plates M are being carried rearfiction will be created between theY danger of the parts sticking, the blunt wedge Y faces acting more or less vas safety valves. In this connection, it will be understood by those skilled in the art that my improvements are capable of use in a mechanism Vither employing a blunt and 'keen angle system of wedge'fa'ces, or wedge faces which are all of the same angle with respect to the axis ofA the mechanism. In release,y the springs B and Jeffectually restore all of the parts'to normal position.

From the `)receding descri ation taken 'in connection with thev drawings,it will be evident that I have yprovidedr a gear having a Aplurality of stages of successivelyV increasing resistance, two stagesof successively increasing preliminary frictional resistance anda third stage of relatively heavier final frictional resistance. This gear is particularly adapted for passengercar service, as abrupt and sudden shocks are entirely eliminated dueto the blending of the different stages of the compression stroke of the mechanism.

While I have herein shown and described to normal .posi- 'all lli() what I now consider :the preferred manner l of carrying out -my invention, the `same 'is yii'ierely illustrative and YI Acontemplate all changes and modifications that come within the scopezof theclaiins appended hereto. Y

yI claim:

l. Iii a friction shock absorbing mechanism, the combination with a column-loadk sustaining membeigof a plurality of alternated, relatively movable and stationary friction elements mounted' on said member, said stationary elements being iixedagainst longitudinal movement with vrespect tothe column load sustaining member; a follower,

said member and follower'being movable relatively toward' and from eachv other; a combined restoring aiidcusliioning 'spring resistance ;'lateral: pressure creating means disposed and operating on the outer sides of said element-s and arranged to exert oppo- Vsite and inward lateral pressure onl said elements upon relative approachof said follower and member;and an auxiliary spring resistance cooperatingwith said'lateral pressure creati-iig means. Y

Q. In a friction shock vabsorbing mechanism, the combination witha friction .shell having interior friction surfaces; o f a jplurality of intercalated frictionl plates arranged in a centrally disposedl group, .cer-

most plates of said group; and successiif'ely operative preliminary `and main spring resistancel elements co-operating with said shoes. Y

3. ln a friction shock absorbing mechaiiism, the combination with a friction shellI having interior, inwardly converging friction surfaces; of a group of intercalated friction plates arranged centrally within the friction shell; certain of said plates'being anchored to the shell; a pair of wedge sys-` tems, disposed at opposite sides of the group of friction plates and co-operating with the friction surfacesof the shell, each wedge system including a wedge pressure transmitting member and a pair of friction wedge shoes, certain of said shoes co-operating with the outermost plates of the group and successively operative preliminary and main spring resistance elements co-operating with said pairs of shoes.

1l. In a friction shock absorbing mechanisin, the combination with a friction shell having interior friction surfaces; of a central group of intercalated friction plates, certain of said plates being anchored to the shell and the remainder of the plates being movable relativelythereto; a wedge system at each side of the group of plates and cooperating with one of the friction surfaces ofthe shell; a main spring resistance; and means for restoring the movable pla-tes to normal position, comprising wear plates interposed between said group of plates and` the corresponding top and bottoni walls of the shell, said wear plates being actuated by saidl main spring during release of the mechanism.

`5. In a railway draft gear. the combination with front and rear limiting stops; of a combined spring cage and friction shell co-operable with certain of said stops; Va main follower co-operating with the remaining stops; a lcentrally arranged lgroup of intercalated, relatively movable friction plates, certain of said plates being stationary with reference to said combined spring cage and friction shell; lateral pressure creating means co-operating with said main follower for compressing said plates, said means including ay pair of friction element-s co-operating with the friction plates; a preliminary spring initially resisting inward movement of said elements; a main spring adapted to be compressed by the movement of said elements after a predetermined` compression of the preliminary sprino.

' 6. In =a friction .shock absorbing mechanism, the lcombination with a friction shell having interior friction surfaces converging inwardly of the mechanism; of a central group of intercalated friction plates, cer- 4with the outermost plates of said group; a `main spring resistance; a spring follower cooperating with the main spring resistance; a preliminary spring resistance interposed between the spring follower and the friction shoes; and limiting stop blocks also interposed between the friction shoes and the spring follower. y l

7. In a friction shock. absorbing mechanism, the combination with a friction shell having interior, inwardlyconverging friccalated friction plates, certain of said plates 'being anchored to the shell; a. wedge system .90 tion surfaces; of a central group of interat each side of the mechanism interposed between the central group of plates and the corresponding friction surface of the shell,

said wedge system including a wedge pres- .sure transmitting memberV having wedge faces disposed respectively at blunt and keen angles with reference to the longitudinal axis of the mechanism; and two pairs .of friction v wedge shoes, certain of said shoes having wedge faces co-opei'ating with blunt'faces of said wedges and the remaining shoes having faces co-ope-rating with the'leen faces of the wedged-certain of said shoes also having longitudinally', disposedv 'friction surfaces `co-operating withthe outermost plates of said group; and successively operative. preliminary and main spring resistance elements co-operating'with said shoes. 8. In a. friction shock absorbing mechanism, the combination with a combined fricy tion shell and spring cage; of friction shoes; wedge means c'o-operatingwith the shoes; relatively movable intercalated frictionvk plates wit-hin the shell, twin Varranged spring resistance elements within the shell, said shell being open at one end to permit entrance therethrough of the spring resistance elements into the spring cage, said cage having the opposite side walls thereof cut away to vpermit lateral displacement of the Y individual members of the spring resistancev elements when assembling the mechanism;

and detachable ystop means for retaining the spring within `the spring cage.` l

9. In a friction shock absorbing mechanism, the combination with a combined friction shell and spring cage; of a friction means oo-operating with the friction shell; twin arranged main springs; a springfollower interposed between the friction means and springs7 said spring follower and l5V springs being insertable through the friction shell into the spring Cage7V and said cage having; openings lat the opposite sides thereof of less width than the outer diameter of the individual units of the twin 10 spring resistance elements to thereby facilitate assembly of the springs within the cage; and detachable abutment means fixed to the shell and engaging the spring fol'- lowery for limiting' outward movement of the spring` follower .and retaining the main springs within the-spring cage.

In Witness that Ifeflaim the foregoing I have hereunto subscribed my namethis 28th day of April 1925. 

